DELMIA人机工程在飞机虚拟维修中的应用（英文）

以目前航空部门普遍采用的DELMIA软件为平台,介绍了虚拟维修技术在飞机维修性设计中的作用,阐述了基于DELMIA软件的交互式虚拟维修流程,以及其中的虚拟场景构建、维修仿真过程和维修性分析、评价技术。     

基于虚拟现实的机械产品维修系统研究

为了提高机械产品的维修效率,文章提出了基于虚拟现实的维修系统,并给出了系统框架。为了实现CAD系统和虚拟维修系统的数据转换,建立了面向虚拟维修的产品层次信息表达模型;将人机交互技术应用到虚拟维修系统中,并设计了人机交互操作流程和产品维修性分析流程。最后,开发了原型系统,并通过刮板输送机验证了系统的有效性。     

基于DELMIA的主减速器及差速器总成装配仿真

针对主减速器及差速器总成装配复杂、精度要求高等问题,文章采用"反装"思路,以DELMIA软件为平台实现虚拟装配。将产品工艺设计与虚拟装配过程同时进行,凸显了并行设计的思想。在对主减速器及差速器总成碰撞干涉检测和甘特图分析的基础上,发现问题并对装配路径和装配节拍提出优化方案;最终生成可用于指导实际生产的装配序列和装配视频。仿真结果表明,运用虚拟装配技术提高了主减速器装配质量、降低了生产成本、缩短了研发和交付周期。     

数控车床维修性分布数学模型的研究

为了探讨数控车床的维修性分布规律，建立了其维修时间分布的数学模型，得出维修性特征函数，进而评价出数控车床的维修性水平。     

数控机床的虚拟维修

数控机床的虚拟维修是虚拟技术在维修中的具体应用,其改变了传统维修的现场作业方式,维修在虚拟环境中进行。主要介绍数控机床虚拟维修的概念、优点、工作流程及所涉及的关键技术。     

数控机床交互式电子技术手册设计

数控机床的维修性在其寿命周期中是一个非常重要的性能,数控机床维修的快速与准确对于延长数控机床的使用寿命、保证其可靠性起到非常重要的作用,而交互式电子技术手册(IETM)是指导维修、方便培训、提高产品维修性的重要保障资源.本文以欧洲标准S1000D为基础,提出数控机床IETM的设计构架,并应用标准化、互操作性、模块化的设计方法设计了数控机床的IETM.     

汽车驱动桥调试作业仿真优化

汽车驱动桥调试是汽车总装配线上的一个重要作业，作业姿势不当会导致操作工人颈部和肩部疾病。利用DELMIA仿真软件对现场工作姿势进行人机工程学分析，并用快速上肢评估（RULA）来确定其风险等级，提出了改进操作的方案，并用仿真软件验证了其效果。结果表明：通过增加工作台阶，可以改善上臂和颈部的姿势，减少了工作紧张的风险；应用DELMIA可以对工作姿势进行量化评估，使分析过程更加直观和科学。     

汽车驱动桥调试作业仿真优化（英文）

汽车驱动桥调试是汽车总装配线上的一个重要作业,作业姿势不当会导致操作工人颈部和肩部疾病。利用DELMIA仿真软件对现场工作姿势进行人机工程学分析,并用快速上肢评估(RULA)来确定其风险等级,提出了改进操作的方案,并用仿真软件验证了其效果。结果表明:通过增加工作台阶,可以改善上臂和颈部的姿势,减少了工作紧张的风险;应用DELMIA可以对工作姿势进行量化评估,使分析过程更加直观和科学。     

液压支架横焊缝焊接专机运动学建模与工艺仿真

研究了大型结构件非标焊接专机的虚拟示教实现问题。在CATIA中建立了液压支架横焊缝焊接专机的系统模型,分析了其运动链组成,建立了其运动学方程,并给出了解算方法和结果;在DELMIA中构建了其真实的虚拟专机,以液压支架焊接工艺为基础,进行了焊接轨迹规划和示教,生成了无干涉的焊接轨迹,完成了液压支架横焊缝焊接的虚拟仿真,为实际设备的现场调试实现提供了作业指导。     

装备维修技术体系初探

针对当前装备维修技术的发展现状,提出了装备维修技术体系。该技术体系包含5大类、3个层次,涵盖了健康管理、故障诊断与评估、损伤修复、维护保养、维修信息化等多方面技术内容。先进检测技术、智能自修复技术、虚拟维修技术、现场应急维修技术等多个技术领域已经成为维修技术的重要发展方向,大力发展绿色维修技术、促进多学科的交叉融合,注重应用基础研究,是促进装备维修技术发展的重要途径。     

Effects of Post-weld Heat Treatment on Microstructure,Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.     

The First Phase of the SRIF Industrialized Base in ＂West Area＂ Has Been Put into Operation

After nearly two years＇ tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry （SRIF）, located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.     

Thermodynamics Study on the Decomposition of Chromite with KOH

Institute of Process Engineering, Chinese Academy of Sciences, China, has proposed a method for oxidative leaching of chromite with potassium hydroxide. Understanding the mechanism of chromite decomposition, especially in the potassium hydroxide fusion, is important for the optimization of the operating parameters of the oxidative leaching process. A traditional thermodynamic method is proposed and the thermal decomposition and the reaction decomposition during the oxidative leaching of chromite with KOH and oxygen is discussed, which suggests that chromite is mainly destroyed by reactions with KOH and oxygen. Meanwhile, equilibrium of the main reactions of the above process was calculated at different temperatures and oxygen partial pressures. The stable zones of productions, namely, K2CrO4 and Fe2O3, increase with the decrease of temperature, which indicates that higher temperature is not beneficial to thermodynamic reactions. In addition, a comparison of the general alkali methods is carried out, and it is concluded that the KOH leaching process is thermodynamically superior to the conventional chromate production process.     

Influence of Heat Treatment on Damping Behaviour of the Magnesium Wrought Alloy AZ61

The effect of isochronal heat treatments for 1h on variation of damping, hardness and microstructural change of the magnesium wrought alloy AZ61 was investigated. Damping and hardness behaviour could be attributed to the evolution of precipitation process. The influence of precipitation on damping behaviour was explained in the framework of the dislocation string model of Granato and Lücke.     

Effect of Rare Earth Doping on Impedance,Modulus and Conductivity Properties of Multiferroic Composites:0.5(BiLa_xFe_(1-x)O_3)–0.5(PbTiO_3)

The Lanthanum-doped bismuth ferrite–lead titanate compositions of 0.5(Bi LaxFe1-xO3)–0.5(Pb Ti O3)(x = 0.05,0.10,0.15,0.20)(BLxF1-x-PT) were prepared by mixed oxide method.Structural characterization was performed by X-ray diffraction and shows a tetragonal structure at room temperature.The lattice parameter c/a ratio decreases with increasing of La(x = 0.05–0.20) concentration of the composites.The effect of charge carrier/ion hopping mechanism,conductivity,relaxation process and impedance parameters was studied using an impedance analyzer in a wide frequency range(102–106Hz) at different temperatures.The nature of Nyquist plot confirms the presence of bulk effects only,and non-Debye type of relaxation processes occurs in the composites.The electrical modulus exhibits an important role of the hopping mechanism in the electrical transport process of the materials.The ac conductivity and dc conductivity of the materials were studied,and the activation energy found to be 0.81,0.77,0.76 and 0.74 e V for all compositions of x = 0.05–0.20 at different temperatures(200–300 °C).     

Using Finite Element and Contour Method to Evaluate Residual Stress in Thick Ti-6Al-4V Alloy Welded by Electron Beam Welding

This work was to reveal the residual stress profile in electron beam welded Ti-6Al-4V alloy plates(50 mm thick) by using finite element and contour measurement methods.A three-dimensional finite element model of 50-mmthick titanium component was proposed,in which a column–cone combined heat source model was used to simulate the temperature field and a thermo-elastic–plastic model to analyze residual stress in a weld joint based on ABAQUS software.Considering the uncertainty of welding simulation,the computation was calibrated by experimental data of contour measurement method.Both test and simulated results show that residual stresses on the surface and inside the weld zone are significantly different and present a narrow and large gradient feature in the weld joint.The peak tensile stress exceeds the yield strength of base materials inside weld,which are distinctly different from residual stress of the thin Ti-6Al-4V alloy plates presented in references before.     

Microstructures and Tensile Properties of Ultrafine-Grained Ni–(1–3.5) wt% SiC_(NP) Composites Prepared by a Powder Metallurgy Route

Silicon carbide nanoparticle-reinforced nickel-based composites(Ni–Si CNP),with a Si CNPcontent ranged from1 to 3.5 wt%,were prepared using mechanical alloying and spark plasma sintering.In addition,unreinforced pure nickel samples were also prepared for comparative purposes.To characterize the microstructural properties of both the unreinforced pure nickel and the Ni–Si CNPcomposites transmission electron microscopy(TEM) was used,while their mechanical behavior was investigated using the Vickers pyramid method for hardness measurements and a universal tensile testing machine for tensile tests.TEM results showed an array of dislocation lines decorated in the sintered pure nickel sample,whereas,for the Ni–Si CNPcomposites,the presence of nano-dispersed Si CNPand twinning crystals was observed.These homogeneously distributed Si CNPwere found located either within the matrix,between twins or on grain boundaries.For the Ni–Si CNPcomposites,coerced coarsening of the Si CNPassembly occurred with increasing Si CNPcontent.Furthermore,the grain sizes of the Ni–Si CNPcomposites were much finer than that of the unreinforced pure nickel,which was considered to be due to the composite ball milling process.In all cases,the Ni–Si CNPcomposites showed higher strengths and hardness values than the unreinforced pure nickel,likely due to a combination of dispersion strengthening(Orowan effects) and particle strengthening(Hall–Petch effects).For the Ni–Si CNPcomposites,the strength increased initially and then decreased as a function of Si CNPcontent,whereas their elongation percentages decreased linearly.Compared to all materials tested,the Ni–Si CNPcomposite containing 1.5% Si C was found more superior considering both their strength and plastic properties.     

Directional Growth of Tin Crystals Controlled by Combined Solute Concentration Gradient Field and Static Magnetic Field

A new method was introduced to achieve directional growth of Sn crystals. Microstructures in liquid(Pb)/liquid(Sn) diffusion couples were investigated under various static magnetic fields. Results show that the β-Sn crystals mainly reveal an irregular dendritic morphology without or with a relatively low static magnetic field(B0.3 T). When the magnetic field is increased to 0.5 T, the β-Sn dendrites close to the final stage of growth begin to show some directional character. With a further increase in the magnetic field to a higher level(0.8–5 T), the β-Sn dendrites have an enhanced directional growth character, but the dendrites show a certain deflection. As the magnetic field is increased to 12 T, the directional growth of the β-Sn dendrites in the center of the couple is severely destroyed. The mechanism of the directional growth of the β-Sn crystals and the deflection of the β-Sn crystals with the application of static magnetic field was tentatively discussed.     

Quantitative Analysis of the Crystallographic Orientation Relationship Between the Martensite and Austenite in Quenching–Partitioning–Tempering Steels

The orientation relationships(ORs)between the martensite and the retained austenite in low-and medium-carbon steels after quenching–partitioning–tempering process were studied in this work.The ORs in the studied steels are identified by selected-area electron diffraction(SAED)as either K–S or N–W ORs.Meanwhile,the ORs were also studied based on numerical fitting of electron backscatter diffraction data method suggested by Miyamoto.The simulated K–S and N–W ORs in the low-index directions generally do not well coincide with the experimental pole figure,which may be attributed to both the orientation spread from the ideal variant orientations and high symmetry of the low-index directions.However,the simulated results coincide well with experimental pole figures in the high-index directions{123}_(bcc).A modified method with simplicity based on Miyamoto’s work was proposed.The results indicate that the ORs determined by modified method are similar to those determined by Miyamoto’method,that is,the OR is near K–S OR for the low-carbon Q–P–T steel,and with the increase of carbon content,the OR is closer to N–W OR in medium-carbon Q–P–T steel.     

Growth Kinetics of Single Inclusion Particle in Molten Melts

On the basis of the single-particle framework, a new theory on inclusion growth in metallurgical melts is developed to study the kinetics of inclusion growth on account of reaction and collision. The studies show that the early growth of inclusion depends on reaction growth and Brawnian motion collision, and where the former is decisive, the late growth depends on turbulence collision and Stokes＇ collision, and where the former is dominant; collision growth is very quick during the smelting process, lessened in the refining process, but nearly negligible in the continuous casting process.